Needle protection device for an injection unit

ABSTRACT

A needle protecting device including a base body, a needle protecting sleeve mounted on the base body, wherein in a protective position the sleeve surrounds an injection needle and in a second position exposes the injection needle, a first block and a second block, one connected to the needle protecting sleeve and the other connected to the base body, wherein in the protective position of the sleeve the blocks engage to prevent the sleeve from moving into the second position, and a safety-release for releasing the engagement of the blocks.

PRIORITY CLAIM

This is a Continuation Application of International Application No.PCT/CH01/00113, filed on Feb. 22, 2001, which claims priority to GermanApplication No. DE 100 09 816.9, filed on Mar. 1, 2000, both of whichare incorporated herein by reference.

BACKGROUND

The invention relates to needle protecting devices for injectiondevices. It also relates to methods of making and assembling a needleprotecting device, and to methods of using a needle protection deviceand an injection device equipped with a needle protection device. In oneembodiment, while in a protective position, the needle holder inaccordance with the present invention surrounds the injection needle ofan injection device and prevents the needle from being unintentionallyexposed.

An injection device comprising a needle protecting device is known fromU.S. Pat. No. 5,609,577. An injection needle is surrounded by a needleprotecting sleeve. The needle protecting sleeve is mounted, axiallyslidably, on a casing of the injection device. In the protectiveposition, the needle protecting sleeve is secured by a block against theinjection needle being unintentionally slid or exposed. Once the blockis released, the needle protecting sleeve can be slid into a rearposition in which the injection needle protrudes freely beyond theretracted needle protecting sleeve. When the needle protecting sleeve isretracted, a tension spring of the needle protecting device is tensed.If the needle protecting sleeve is relaxed after the injection, then theneedle protecting sleeve pre-latches back into its protective positionunder the tension stress of the tension spring. The blocking mesh orconnection is automatically re-established in the protective position.

The block is formed by a cam and a guideway for the cam. The guidewayconsists of one section extending axially, and another section connectedto it at a right angle. In the protective position, the cam meshes withthe angled section of the guideway. In this way, the needle protectingsleeve is prevented from sliding and exposing the injection needle. Forreleasing the block, the needle protecting sleeve is rotated relative tothe base body until the cam comes to rest in the axially extendingsection of the guideway. In this rotational position, the needleprotecting sleeve can be slid relative to the base body, into the rearposition. The tension spring does not only serve to pre-tension theneedle protecting sleeve into the front position. Simultaneously, italso tenses the needle protecting sleeve into the rotational position inwhich the cam abuts in the angled section of the guideway. Thus, forinjecting, the needle protecting sleeve is first rotated against theforce of the tension spring and then, likewise against the force of thetension spring, slid into its rear position.

In the known needle protecting device of the '577 patent, the tensionspring is a substantial element of the block. By using a spring tosecure the needle protecting sleeve in its protective position, acomplicated construction is required for the blocking mechanism.Furthermore, the normal functioning of the blocking mechanism issubstantially dependent on the spring. The spring can for instance breakor jam. If the spring malfunctions, it cannot be guaranteed that theneedle protecting sleeve is securely blocked.

SUMMARY

It is an object of the invention to provide a needle protecting devicefor an injection device, which in a protective position securely blocksa needle protecting sleeve against sliding, and which is not susceptibleto faults. Preferably, a blocking mechanism should require a minimalnumber of movable parts, and be designed simply.

In one embodiment, the present invention provides a needle protectingdevice for an injection device comprising a sleeve-shaped base body, aneedle protecting sleeve operably coupled to the base body, wherein, ina protective position, the needle protecting sleeve surrounds aninjection needle of the injection device and, in a second position,exposes the injection needle, a first block and a second block, one ofwhich is immovably connected to the needle protecting sleeve and theother of which is immovably connected to the base body, wherein, in theprotective position of the needle protecting sleeve, a blocking mesh isformed by the blocks pushing axially against each other, the blockingmesh preventing the needle protecting sleeve from sliding into thesecond position, and a safety-release for the blocking mesh, wherein thefirst block is formed by a bendable latch connected substantiallyrigidly to one of the needle protecting sleeve and base body and whereinthe blocking mesh is released by bending the latch.

In one embodiment, a needle protecting device in accordance with thepresent invention comprises a sleeve-shaped base body and a needleprotecting sleeve. An injection needle of the injection device protrudesbeyond a front end of the base body. The needle protecting sleeve ismounted, axially slidably, on the base body. In a protective position,the needle protecting sleeve surrounds the injection needle. Once it hasbeen axially slid into a rear position, the needle protecting sleeveexposes the injection needle. In the protective position, the needleprotecting sleeve is blocked against retracting relative to the basebody and the injection needle. In the protective position of the needleprotecting sleeve, a blocking mesh (i.e., engagement, joint, connection,etc.) exists between a first blocking means and a second blocking means,in that the two blocking means push against each other axially. One ofthe blocking means is connected non-sliding to the needle protectingsleeve and the other blocking means is connected non-sliding to the basebody. The blocking mesh thus prevents the needle protecting sleeve fromsliding from the protective position to the rear position. Lastly, theneedle protecting device comprises a safety-release means for releasingthe blocking mesh between the first blocking means and the secondblocking means.

In accordance with the invention, the first blocking means is formed byan elastically bendable latch which is rigidly connected to the needleprotecting sleeve or the base body. In the protective position of theneedle protecting sleeve, the latch abuts the second blocking means,which forms a latch stopper, in the axial direction. The blocking meshof the blocking means is released by bending the latch. The latch isbent out of blocking mesh (i.e., engagement, connection, etc.) with thelatch stopper. By being bent, the latch is elastically tensed, i.e., arestoring force is generated in the latch. The latch is preferably fullyrelaxed in its blocking position, which it assumes in the protectiveposition of the needle protecting sleeve.

For securely blocking, the needle protecting device in accordance withthe invention requires only the elastically bendable latch and the latchstopper. A third element, for example in the form of the tension springknown from the prior art, is not required. The number of parts requiredfor manufacturing the block is reduced. The latch in accordance with theinvention combines the blocking function of the known cam and therestraining and/or securing function of the known spring.

In one embodiment, the second blocking means is formed on a surface areaof the base body or of the needle protecting sleeve. The blocking meansis a wall, which protrudes in a radial direction or exactly radially outfrom the surface area or into the surface area. The surface area can bean inner surface area or an outer surface area of the base body or aninner surface area or an outer surface area of the needle protectingsleeve. In one embodiment, the wall forming the second blocking means isformed on an inner surface area of the base body. The second blockingmeans can be formed by a single wall or also by a number of walls, inparticular as described above.

In another embodiment, the safety-release means is mounted on the basebody, slideably movable relative to the needle protecting sleeve. Asliding mount is formed such that the safety-release means slides alongthe latch when moved and so presses on the latch in such a directionthat the latch is bent out of its blocking mesh (i.e., engagement,connection, etc.) The pressure on the latch acts perpendicular to thedirection in which the safety-release means is moved. The safety-releasemeans can, however, also be formed like a push-button or other suitablemechanism which pushes against the latch in the direction in which thepush-button itself moves relative to the base body. Although thesafety-release means can also form the latch stopper itself, and in thiscase is itself moved out of the blocking mesh when released, a separatelatch stopper is provided which is connected to the needle protectingsleeve or the base body, axially non-sliding. In one embodiment, thelatch stopper lies next to sliding path of the safety-release means. Itis a stopper which is rigidly connected to the base body.

A needle protecting device comprising a safety-release means moveablyarranged relative to the needle protecting sleeve exhibits the advantagethat the needle protecting sleeve itself does not have to be operated inorder to release the blocking mesh of the blocking means. Thus, a userno longer has to then pay attention to the release of the blocking meshwhen the needle protecting sleeve is already pressed against the skinfor the injection, as is the case when using the needle protectingsleeve of U.S. Pat. No. 5,609,577. Releasing the blocking mesh andretracting the needle protecting sleeve can be separated from each otherby the movably arranged safety-release means. Furthermore, the blockingmesh can be released and re-established any number of times, while theneedle protecting sleeve remains in the protective position. It is notnecessary for an injection to be performed once the blocking mesh isreleased in order to restore the blocked protective position.

In one embodiment, the safety-release means is secured in the protectiveposition of the needle protecting sleeve such that it is not slaved bythe needle protecting sleeve when the needle protecting sleeve movesinto its protective position. In this way, the safety-release means isadvantageously also secured against being unintentionally moved, forexample due to vibrations. The safety-release means is secured by alocking mesh between the safety-release means and the base body in theprotective position of the needle protecting sleeve. Correspondingly,the base body is provided with a first locking mesh means, and thesafety-release means with a second locking mesh means. The locking meshcan be released.

In one embodiment, the needle protecting device is formed such thatafter an injection, the needle protecting sleeve advances again into theprotective position and the blocking mesh of the latch and the latchstopper in accordance with the invention is automatically established inthe protective position. The needle protecting device allows repeatedinjections, wherein the blocking mechanism automatically blocks theneedle protecting sleeve in its protective position against beingunintentionally retracted. When it is retracted into the rear position,the needle protecting sleeve slaves the safety-release means as far as aposition in which the safety-release means locks with the base body. Byforming the locking mesh so that it can be released, it is possible tooperate the needle protecting device repeatedly. In principle, however,it would also be possible to design the locking mesh of thesafety-release means to be non-releasable. In the case of anon-releasable locking mesh, a needle protecting device comprising alatch, which automatically pre-latches into the blocking stopper, couldonly be used for an injection if it is ensured that the blocking mesh ofthe latch cannot be released in any way other than by the safety-releasemeans. The safety-release means is preferably slaved by the needleprotecting sleeve pressing loosely against the safety-release means whenthe needle protecting sleeve is retracted.

In one embodiment, the latch is formed as an axially extending latchfinger comprising a front-facing abutting area. It is formed as onepiece together with the base body, or as one piece together with theneedle protecting sleeve. In another embodiment, the latch could alsoproject in a radial direction from the base body or the needleprotecting sleeve.

The blocking mechanism of the needle protecting sleeve can comprise anumber of latches, for forming a number of blocking meshes withcorresponding blocking stoppers. A number of safety-release means, i.e.,at least one for each latch, can be arranged non-sliding relative toeach other on a common base, such that by appropriately operating thebase, all the blocking meshes can be released simultaneously. The numberof safety-release means can, however, also be mounted and operableindependently of each other, in order for example to even more securelyprevent the blocking meshes from being unintentionally released.

In one embodiment, the blocking mechanism is surrounded by a sleeveportion of the base body, such that only the safety-release means can beaccessed from without. The sleeve portion of the base body in questionfulfils the function of a covering sleeve. The needle protecting sleeveis pushed into the covering sleeve when sliding into the rear position,but in that position can still protrude some way beyond the coveringsleeve.

In another embodiment, a cam projects from the safety-release means andthrough an opening of the covering sleeve, and the safety-release meansis slidable along the covering sleeve. The cam is supported on the outersurface of the covering sleeve, which prevents a radially inwarddirected pressure being exerted on the safety-release means when it isoperated. The forces acting when the safety-release means is operatedare thus collected by the covering sleeve.

The base body can be formed as one or a number of parts. When the basebody is formed as a number of parts, said number of parts are connectedto each other, axially non-sliding. The base body can be formed by thecasing of the injection device, as is the case in the needle protectingdevice of U.S. Pat. No. 5,609,577. In another embodiment, the needleprotecting device is formed as an independent device whose base body isadapted to a casing of an injection device, such that the base body maybe connected, non-sliding, to the casing of the injection device. Such aneedle protecting device, which may be independently handled, comprisesa base body, which is simply pushed onto the casing of the injectiondevice and fixed non-sliding to the casing. It is advantageous to form aplug-on sleeve which is very simply plugged onto an existing injectiondevice, up against a stopper, and then fixed to the casing of theinjection device in a positive and frictional lock. By appropriatelyadapting the shape of its base body, the independent needle protectingdevice can advantageously serve for retro-fitting existing injectiondevices which allow injection even without a needle protecting device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a needle protecting device;

FIG. 2 is a longitudinal section of the components of the needleprotecting device of FIG. 1;

FIG. 3 is a perspective representation of the components of FIG. 2;

FIG. 4 depicts the covering sleeve of the needle protecting deviceaccording to FIGS. 1 to 3;

FIG. 5 is a longitudinal section of the needle protecting deviceaccording to FIGS. 1 to 4 in its assembled state; and

FIG. 6 is a detail from FIG. 5.

DETAILED DESCRIPTION

FIG. 1 shows a needle protecting device in its assembled state. Aplug-on sleeve 2, a covering sleeve 10 and a needle protecting sleeve 20in a co-axial arrangement may be recognized. The covering sleeve 10 islatched onto the plug-on sleeve 2. The latching connection canpractically no longer be released. When assembled, the plug-on sleeve 2and the covering sleeve 10 can be regarded as a single base body 2, 10.No sliding movements are possible, in particular between the plug-onsleeve 2 and the covering sleeve 10. The needle protecting device may beplugged Onto an injection device for administering a product fluid, inparticular a medicinal fluid, for example insulin. To this end, theplug-on sleeve 2 is formed adapted to the injection device in question.

The needle protecting sleeve can be slid back and forth in the axialdirection within the covering sleeve 10. In FIG. 1, it assumes aprotective position. In the protective position, the needle protectingsleeve 20 is extended up to a stopper formed within the covering sleeve10 and surrounds an injection needle of the injection device up to andbeyond a tip of the needle. In the protective position, the needleprotecting sleeve 20 protects the user from injuries from the injectionneedle. At the same time, the injection needle is protected from beingdamaged. In the protective position, the needle protecting sleeve 20furthermore forms a blind, such that the user cannot see the injectionneedle. In particular, this reduces the inhibition threshold to beobserved in users who inject the product themselves.

In the protective position, the needle protecting sleeve 20 is blockedagainst sliding into the covering sleeve 10. This blocking prevents theneedle protecting sleeve 20 from being unintentionally retracted and theinjection needle exposed. Directly before an injection, the user has torelease the block on the needle protecting sleeve 20, i.e., he has torelease the safety on the needle protecting sleeve 20. This is done byaxially sliding an operating element 36. Once the block is released, theneedle protecting sleeve 20 can be retracted, against an elasticrestoring force relative to the plug-on sleeve 2 and the covering sleeve10, into a rear position. In the rear position, the needle protectingsleeve 20 exposes the injection needle. The needle protecting sleeve isretracted in the course of insertion during the injection. If theinjection needle is withdrawn again out of the tissue after theinjection, the needle protecting sleeve 20 is advanced again by theelastic restoring force. As soon as the needle protecting sleeve 20 hasreached its protective position again, it is automatically re-blocked.The block can be repeatedly released.

FIGS. 2, 3 and 4 show the components of the needle protecting deviceindividually, before being assembled. The needle protecting device isformed by five components, namely the plug-on sleeve 2, the coveringsleeve 10, the needle protecting sleeve 20, a safety-release means 30and a restoring element in the form of a pressure spring 29, whichhowever is only shown in FIG. 5. In one embodiment, however, once thesefive components have been assembled, the operating element 36 still hasto be connected to the safety-release means 30. The four components 2,10, 20 and 30 and also the operating element 36 are each embodied in onepiece as plastic injection parts.

The plug-on sleeve 2 comprises a whole, first sleeve region 3 and asecond sleeve region comprising two sleeve segments 7 and a ring 8. Thetwo sleeve segments 7 project from a facing area of the first sleeveregion 3, offset by 180°. The two sleeve segments 7 are distanced fromeach other at their ends by the ring 8 and thus the second sleeve regionis reinforced. In a transition region between the first sleeve region 3and the sleeve segments 7, a recess or groove 4 is formedcircumferentially. Lastly, the two sleeve segments 7 each comprise atangentially extending swelling or bulge 6 near their ends on theirouter surface areas.

The covering sleeve 10 comprises a surface area which is broken only bytwo opposing openings 14. In the vicinity of the end of the coveringsleeve 10, a swelling or bulge 13 runs around the inner surface area. Inthe assembled state, the bulge 13 comes to rest in the groove 4 of theplug-on sleeve 2. At the other end of the covering sleeve 10, two collarsegments 15 project radially inwards. The two collar segments 15 serveas front stoppers and as linear guides for the needle protecting sleeve20.

On the inner surface area of the covering sleeve 10, two stoppers 16 areformed in a symmetrical arrangement and offset by 180° with respect toeach other. The stoppers 16 are each formed by a pair of areas facingthe end of the covering sleeve 10 and pointing radially to the innersurface area of the covering sleeve 10. Viewed in the axial direction,the stoppers 16 are arranged between the openings 14 and the collarsegments 15. Furthermore, two straight, axially extending channels 17are formed in the inner surface of the covering sleeve 10. Each one ofthe openings 14 extends through one of the channels 17 and sub-dividesthe respective channel into a first channel section 17 a and a secondchannel section 17 b. The stoppers 16 directly border the second channelsection 17 a of each of the channels 17 and thus each form one edge ofthe channel edging. One inner surface region 11 of the covering sleeve10 is extended toward another inner surface region 12. The transition isformed by a circumferential collar interrupted by the channels 17.

The needle protecting sleeve 20 exhibits the shape of a cap, by forminga base at its rear end, said base being broken only by a central opening21 for the injection needle. Two latches 24, axially free, project froma facing area of the needle protecting sleeve 20 in a symmetricalarrangement and offset by 180°. The latches 24 each radially protrudeslightly beyond an outer surface area of the needle protecting sleeve20. The latches 24 are each formed in an exposed notch 25 of the surfacearea of the needle protecting sleeve 20. In one embodiment, the latches24 are each laminate. In one embodiment they are rectangular laminae. Inanother embodiment, the latches are a single layer. At their rear ends,the latches 24 are tapered or angled in a central region 26 on theiroutward pointing upper sides. The latches 24 are elastic in the radialdirection around their foot regions.

Lastly, the needle protecting sleeve 20 comprises a recessed face region22 on its outer surface area, said face region 22 tapering off towardsthe end of the needle protecting sleeve 20 and forming a collar 23 tothe rest of the outer surface area at one end. Another recessed faceregion 22 is formed in the same way on the diametrically opposing sideof the needle protecting sleeve 20.

The safety-release means 30 is formed by a ring 31 and two tongues 32projecting axially from the ring 31 and arranged symmetrically, offsetby 180° with respect to each other. A recess or groove 34 runs aroundthe inner surface area of the ring 31. A cam 35 projects outwards fromeach of the outward pointing surfaces of the tongues 32. An operatingelement 36 is attached to each of the cams 35. In one embodiment, theoperating elements 36 are only attached to the cam 35 after the fourcomponents 2, 10, 20, 30 have been assembled.

When assembling the device, the needle protecting sleeve 20 is firstpushed into the covering sleeve 10. The two collar segments 15 togetherwith the recesses 22 form a linear guide for the needle protectingsleeve 20. The co-operation between the collar segments 15 and the tworecesses 22 simultaneously ensures that as soon as it is inserted, theneedle protecting sleeve 20 assumes a rotational position relative tothe covering sleeve 10 such that the latches 24 are aligned with thestoppers 16. Due to their radially projecting length in the innersurface region 12 of the covering sleeve 10, the latches 24 are bentradially inwards against their own elastic restoring forces. As soon asthe latches 24 have been pushed over the stoppers 16, they pre-latchradially outwards again due to their own elastic restoring forces, suchthat their facing areas then oppose the stoppers 16, directly facingthem. In this blocking mesh (i.e., engagement, connection, etc.) of thelatches 24, it is no longer possible to retract the needle protectingsleeve 20 relative to the covering sleeve 10. The latches 24 then lie infront of the stoppers 16 in an enlargement 18 of the channel section 17b of the covering sleeve 10. More precisely, only the edge regions ofthe latches 24 remaining to the left and right of the angled centralregion 26 push against the stoppers 16 in the blocking mesh. If theneedle protecting sleeve 20 is advanced slightly further, then thecollars 23 push against the collar segments 15. The co-operation betweenthe collar segments 15 and the collars 23 is principally intended toprevent the needle protecting sleeve 20 from being able to fall forwardsout of the covering sleeve 10. The latches 24 are, however, stillaccessible from without, from the facing side of the covering sleeve 10using a pointed tool.

In the next assembly step, the safety-release means 30, in therotational position relative to the other components as shown in FIG. 3,is likewise pushed into the covering sleeve 10, behind the needleprotecting sleeve 20. As it is inserted, the tongues 32 are guidedtightly and laterally into the channels 17. Insertion is complete whenthe cams 35 reach the region of the openings 14 and the tongues 32 aretherefore able to pre-latch outwards.

The operating elements 36 are then adhered to the cams 35 or securelyattached in some other way. The operating elements 36 are shaped suchthat they press against the outer surface area of the covering sleeve 10and so keep any radial pressure during operation off the tongues 32. Theoperating elements 36 thus also simultaneously serve to support thesafety-release means 30 and/or the tongues 32 on the covering sleeve 10.The operating elements 36 can also be formed as one piece on the cams35, for example mushroom-shaped. In such an embodiment, they would beplaced against the respective cam once they have been passed through theopenings 14 and once passed through would elastically expand, inparticular shore up, to achieve the support.

Before the covering sleeve 10 is connected to the plug-on sleeve 2, thepressure spring 29 (FIG. 5) is inserted into the pre-assembled needleprotecting sleeve 20 as far as the base of the needle protecting sleeve20.

In a last assembly step, the covering sleeve 10, comprising thecomponents 20 and 30 and the pressure spring 29, is pushed onto theplug-on sleeve 2 until the bulge 13 is locked into the groove 4. Sincethe covering sleeve 10 is not broken in the region of the bulge 13, anddue to a sufficient rigidity overall, the locking connection between thegroove 4 and the bulge 13 cannot be released again, at least not withouttools or without destroying it.

If the safety-release means 30 does not yet assume the locking positionshown in FIG. 5, then the needle protecting sleeve 20 can be retractedinto its rear position, for example within the context of functionaltesting by the manufacturer. The needle protecting sleeve 20 presses thesafety-release means 30 into the rear locking position such as thesafety-release means 30 assumes in the representation in FIG. 5. Thesafety-release means 30 is slaved by the needle protecting sleeve 20pressing with a facing side 27 against a facing side 33 of thesafety-release means 30 facing towards it. The two bulges 6 meshing withthe groove 34 of the safety-release means 30 establishes a releasablelocking connection. The locking connection is nonetheless sufficientlyfirm to prevent it being released due to the vibrations, jerking and thelike which commonly occur during use.

The function of the needle protecting device is best seen from FIGS. 5and 6. FIG. 5 shows the needle protecting device completely assembledand attached to an injection device (not shown). The plug-on sleeve 2surrounds an ampoule holder 1. The ampoule holder 1 is sleeve-shaped andaccommodates an ampoule which is filled with a medicine fluid. Theampoule holder 1 is inserted into the plug-on sleeve 2 up to the ring 8.The segments 7 (FIG. 3) allow the ampoule holder 1 to be viewed. Aninjection needle 40 connected in the usual way to an outlet of theampoule protrudes beyond the ends of the plug-on sleeve 2 and of thecovering sleeve 10. In the representation in FIG. 5, the needleprotecting sleeve 20 assumes its protective position, in which itprotectively surrounds the injection needle 40 over its entire length.The latches 24 oppose their respective stopper 16, facing them axially,i.e., they abut their respective stopper 16. The safety-release means 30assumes its locking position, in which there is no mesh (i.e.,engagement, connection, etc.) between the tongues 32 and the latches 24.The needle protecting sleeve 20 is thus blocked against retracting.

An annular space 9 is formed between the sleeve segments 7 and thecovering sleeve 10, into which space the needle protecting sleeve 20 canbe slid up to its position if the blocking mesh between the latches 24and the stoppers 16 has been released beforehand. This is released bysliding the safety-release means 30.

In the following, the functional sequence in an injection will bedescribed, wherein reference is to be made at all times to all thefigures.

Once a protective cap still surrounding the injection needle 40 has beenremoved, a first injection can be performed.

Directly before the injection, the user pushes the safety-release means30 in a releasing direction by means of the operating elements 36. Inthe course of sliding the safety-release means 30, each of the tongues32 slides over the latch 24 assigned to it. Since the latches 24protrude outwards beyond the sliding contact areas of the tongues 32facing them, the latches 24 are pressed radially inwards when thetongues 32 slide past the latches 24 with their sliding contact areas.The safety-release means 30 is advanced as far as an end position,wherein the latches 24 are bent away from the stoppers 16, such that theneedle protecting sleeve 20 can be pushed into the annular space 9, thelatches 24 pressing elastically against the tongues 32. The tongues 32are as wide as the tapered or angled central regions 26 (FIG. 3) of thelatches 24. The tongues 32 are likewise tapered towards their facingareas. Tapering the latches 24 or the tongues 32 or both particularlysecurely prevents self-locking which could impede sliding over thelatches 24.

Once the block on the needle protecting sleeve 20 has been released, theinjection device is placed on the skin, such that the needle protectingsleeve 20 lies on the skin via its base and the injection needle 40points to the surface of the skin approximately perpendicularly. In thisinjecting position, the needle protecting sleeve 20 is slid into theannular space 9 as far as a rear position by the pressure of theinjection device against the surface of the skin. Simultaneously, theinjection needle 40 pierces the skin and penetrates into the tissuebelow.

As the needle protecting sleeve 20 is slid into the annular ring 9, afacing area 27 (FIG. 2) of the needle protecting sleeve 20 meshes withthe facing area 33 of the safety-release means 30. The mesh consists ofa loose abutting of the two facing areas 27 and 33. In this way, theneedle protecting sleeve 20 presses the safety-release means 30 into thelocking position shown in FIG. 5, in which the two bulges 6 mesh withthe recess 34. If, after the injection, the injection needle iswithdrawn from the tissue again and the needle protecting device isrelaxed, then the needle protecting sleeve 20 slides back in theneedle-protecting direction due to the force from the pressure spring29. As the needle protecting sleeve 20 is moved, the safety-releasemeans 30 remains in its locking position. As soon as the needleprotecting sleeve 20 has been advanced far enough that the latches 24pass in front of the stoppers 16, the latches 24 latch back radiallyoutwards due to the restoring forces generated in them by being bentaway, such that they again oppose the stoppers 16 and the blocking meshis re-established.

The injection device can be disposed of together with the needleprotecting sleeve in its blocked protective position. Even in the caseof repeated injections, the needle protecting device likewise fulfillsits protective function. Lastly, the needle protecting device can alsobe used in combination with a number of injection devices in succession.In principle, it can even be used with various injection devices in anembodiment as a plug-on device, if the plug-on sleeve 2 is adapted inits shape to the respective injection device. For the majority ofinjection devices, it can be assumed that the ampoules exhibitapproximately the same cross-sections, such that it is only actuallynecessary to adapt the plug-on sleeve 2.

In the foregoing description, embodiments of the invention have beenpresented for the purpose of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed. Obvious modifications or variations are possible in light ofthe above teachings. The embodiments were chosen and described toprovide the best illustration of the principals of the invention and itspractical application, and to enable one of ordinary skill in the art toutilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. All suchmodifications and variations are within the scope of the invention asdetermined by the appended claims when interpreted in accordance withthe breadth they are fairly, legally, and equitably entitled.

1. A needle protecting device for an injection device, said needleprotecting device comprising: a) a sleeve-shaped base body; b) a needleprotecting sleeve which is mounted, axially slidably, on said base body;c) wherein, in a protective position, said needle protecting sleevesurrounds an injection needle of said injection device and, in a secondposition, exposes said injection needle; d) a first blocking means and asecond blocking means, of which one is connected non-sliding to saidneedle protecting sleeve and the other is connected non-sliding to saidbase body; e) wherein, in said protective position of said needleprotecting sleeve, a blocking mesh is formed by said blocking meanspushing axially against each other and so preventing said needleprotecting sleeve from sliding into said second position; f) and asafety-release means for releasing said blocking mesh, wherein g) saidfirst blocking means is formed by an elastically bendable latch which isconnected rigidly to said needle protecting sleeve or said base body; h)and in that said blocking mesh of said blocking means is released bybending said latch against a restoring force generated in said latch bybending it.
 2. The needle protecting device as set forth in claim 1,wherein the base body is connected, non-sliding, to a casing of theinjection device.
 3. The needle protecting device as set forth in claim1, wherein the base body is formed by a casing of the injection device.4. The needle protecting device as set forth in claim 1, wherein saidsafety-release means is mounted on said base body, movable relative tosaid needle protecting sleeve.
 5. The needle protecting device as setforth in claim 1, wherein said safety-release means is mounted on saidneedle protecting sleeve, movable relative to said base body.
 6. Theneedle protecting device as set forth in claim 1, wherein saidsafety-release means is mounted on said base body, slidable relative tosaid needle protecting sleeve, in such a way that when moved, it slidesalong said first blocking means and bends said first blocking means outof said blocking mesh.
 7. The needle protecting device as set forth inclaim 1, wherein a locking mesh exists between said safety-release meansand said base body in said protective position of said needle protectingsleeve, which secures said safety-release means against being slaved bysaid needle protecting sleeve moving to said protective position.
 8. Theneedle protecting device as set forth in claim 7, wherein said lockingmesh of said safety-release means can be released.
 9. The needleprotecting device as set forth in claim 1, wherein said needleprotecting sleeve slaves said safety-release means as it slides intosaid second position, until said safety-release means enters into alocking mesh with said base body.
 10. The needle protecting device asset forth in claim 9, wherein said locking mesh of said safety-releasemeans can be released.
 11. The needle protecting device as set forth inclaim 1, wherein said needle protecting sleeve presses loosely againstsaid safety-release means and slaves said safety-release means as itslides into said second position.
 12. The needle protecting device asset forth in claim 1, wherein said first blocking means projects axiallyfrom said needle protecting sleeve or said base body, may be bentradially, and in said protective position of said needle protectingsleeve is bent out of said blocking mesh, against its elastic restoringforce.
 13. The needle protecting device as set forth in claim 1, whereinsaid second blocking means is formed on a surface area of said base bodyor of said needle protecting sleeve.
 14. The needle protecting device asset forth in claim 1, wherein said safety-release means pushes over saidfirst blocking means and bends radially inwards, to release saidblocking mesh.
 15. The needle protecting device as set forth in claim 1,wherein: said base body comprises a covering sleeve into which saidneedle protecting sleeve can be moved; said covering sleeve comprises anopening; and a cam of said safety-release means protrudes through saidopening.
 16. The needle protecting device as set forth in claim 15,wherein said cam is supported on an outer surface area of said coveringsleeve against a movement directed radially inwards.
 17. The needleprotecting device as set forth in claim 1, wherein: said base bodycomprises an inner sleeve region and a covering sleeve which surroundssaid inner sleeve region; an annular space remains between said innersleeve region and said covering sleeve; and said needle protectingsleeve may be slid into said annular space.
 18. The needle protectingdevice as set forth in claim 1, wherein a restoring element is supportedon said base body and said needle protecting sleeve, said restoringelement being tensed when said needle protecting sleeve is slid intosaid second position and advances said needle protecting sleeve out ofsaid second position into said protective position.
 19. The needleprotecting device as set forth in claim 1, wherein said base body may beplugged onto a casing of an injection device.